Railway-traffic-controlling apparatus



June 7 1927.

- 1,631,808 R. M. GILSON RAILWAY TRAFFIC CONTROLLING APPARATUS FiledAug.l9. 1924 2 Shae t 1 IINVENTOR t I ATTORNEY 1927. lune 7 R. M. GILSONRAILWAY TRAFFIC CONTROLLING APPARATUS BY Q-K-W Filed Aug. 19, 1924 2Sheets-sheet 2 M a ATTORNEY Patented June 7, 192'?a UNITED STATES PATENTOFFICE.

ROBERT M. GILSON, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH 8?; SIGNAL COMPANY, PENNSYLVANIA.

OF, SWISSVALE, PENNSYLVANIA, A CORPORATION OFRAILWAY-TRAFLIC-GONTROLLING APPARATUS.

Application filed August 19, 1924. Serial No. 732,927.

l; y invention relates to railway traffic controlling apparatus andparticularly to apparatus of the type comprising train carried governingmechanism controlled by energy received from the trackway. Moreparticularly, my invention relates to apparatus of the type in whicnalternating currents of two different frequencies are present in thetraclrway, current of one frequency being iii to control the trackwayapparatus and cur cut of the other frequency being used to control thetrain carried governing mechanism.

I will describe two forms of traclrway apparatus embodying my invention.and will then point out the novel features thereof in claims.

in the accompanying drawings, Fig. lis a diagrammatic View showing oneform of apparatus applied to a double track railway and en'ibodying myinvention. F 1g. 2 me view showing a stretch of single track providedwith trackway apparatus en'ibodymg mv invention.

Similar reference characters refer to similar parts in both views.

Referring first to 1, the reference characters X. and Y designate thetwo tracks of double tracltrailway, over each of which tracks trafficnormally moves in the direction indicated by the arrows. The two rails land l of track Y are divided, by means of ii 'ulated joints 3 into aplurality of sucive track sections A.B, B-C, etc. arlv the track rails 2and 2 of track X t divided by means of insulated joints 3, a pluralityof successive sections D-l3l E-lhhtc= here shown. the junction of eachtwo sections of track X is opposite the junction of two sections oftrack Y, although this particular arrangement is not essentlal.

Each-of the tracks X and Y is intended for usev in a railway systemhaving electric propulsion, and for this reason impedance bond of ausual and well known form are prcvidedat the junction of each twoadjacent track sections for thepurpose of coinlucting propulsion currentaround the insulated joints 3. The apparatus of my i1 i-. 'veutionequally well suitech'however, for

use on a steam road, in which case the bonds l t would of course beomitted.

Isleans are provided ior at times supplying each track section of eachtrack wlt-h alter-' prising two line wires l3 and 18 is supplied withalternating current of one frequency from a suitable source such as analternator K. A second transmission line comprising two line wires 12and 1 is constantly supplied with alternating current of a lilferentfrequency from a suitable source such as an alternator J. Currentsupplied from line wires 13 and 13 is used to control train carriedgoverning mechanism of, some suitable type and I shall hereafter callsuch current the train governing current. Alternating current suppliedto the trackway from line wires 12 and 12 is used to control trackwayapparatus and I shall hereafter term such current the track circuitcurrent; The train governing current is preferably, though notnecessarily, of

ondary winding 5 connected across the terminals of the impedance bondlet adjacent the entrance end of the section. A11 impedance 6 isinterposed between the secondary 5 of each transformer T and one rail ofthe associated section in'the usual manner. The

primary l of each track transformer T'is constantly supplied with trackcircuit current from line wires 12 and 12.

Train governing current is supplied to the rails of each section.through the medium of a train governing transformer designated by thereference character S with an appropriate exponent and having asecondary winding 8 connected with the terminals of the impedance bond14 adjacent the exit end of the-section. An impedance 9 is interposedbetween the secondary 8 of each transformer S and one rail ofthecorresponding. section in accordance with standard practice. The supplyof train governingcurrent. to each transformer S will be explained indetail hereinafter. "Each track'section is further provided with a trackrelay designated by the reference character R with an exponentcorresponding to the location and comprising two windings l0 and 11. Onewinding 10 of the relay R is constantly supplied with current from linewires 12 and 12 The remaining winding 11 of each track relay R isconstantly connected across the rails adjacent the exit nd of theassociated section. Inasmuch as each track relay can be effectively Jill-track transformer former S energized only when currents of the samefrequency are supplied to its two windings l0 and 11, it follows thatthese relays will not normally respond to train governing current in thetrack rails.

Each track section is also provided with a line relay desig'natedby thereference char acter H with a suitable distinguishing e2:- penent, whichrelay, as here shown, is located at the entrance end of the associatedsection. Relay H for section DE is provided With a circuit whichincludes contact 70 oi? track relay R for the same section, so thatrelay H is de-energized whenever the associated section is occupied by atrain. The control of relay H may be carried l'arthcr in ad- Vance ifdesired. The circuits for the remaining line relays H may be similar tothe circuit for relay H but are omitted to simplify the drawing. Eachtrain governing transformer S is supplied with train governing currentwhen the associated track relay R is tie-energized and the adjacent linerelay H is energized. it will thus be plain that each train governing'transiormer S is normally disconnected from its energizing source butis connected with such source whenthe corresponding section is occupiedprovided the next section in advance is unoccupied.

As shown in the drawing all parts of the apparatus are in the normalconditions, that is, the conditions corresponding to the un occupiedcondition of the tracks X and Y. This being so, each track section issupplied wth track circuit current from the associated T, all trackrelays are energized, all line relays H are energized, but the circuitvfor each train governing transformers is open at the back contact 17 ofthe corresponding track relay. 1 will now assume that a train passesover track Y moving in the direction of the arrow. As this train enterssection AB, track relay R becomes de-energized. The closing of backcontact 17 thereon completes the circuit for the primary 7 0i traingoverning transformer S and train governing current is thus supplied tosection AB by trans- If, however, when a train enters section A.- B,section B@ is already occupied, the opening of the front contact 71 ofline relay H will interrupt the primary circuit for. transformer S andso the closing of back contact 17 of track relay R will not result insupplying train governing current to section AB.

' The traokway apparatus herein shown and taln systems s described issuitable for cooperation with train carried governing mechanism arrangedto be responsive to train governing current in the trackway, that is,current of the fr=- quency of alternator K. This governing mechanism ispreferably arranged to give a le s restrictive indication when theportion of tracliway occupied by the train is being supplied with traingoverning current, and to display a more restrictive indication when thesupply oi. train governing current to such portion of track isinterrupted. In cerabic for co'operation in this manner the traincarried governing mechanism is controlled by the trackway currentthrough the medium of suitable pick-up apparatus carried on the train inadvai'ice of the :lront axle. It is obvious that in systems of this cha'acter the source of train govern ing current must at all times belocated. in advance of the train, as otherwise the train governingcurrent would be shunted away from the receiving"apparatus by the wheelsand axles of the train itself. p

Under certain conditions oi operation, with the circuits illustrated inFig. 1, train governing current may be supplied to a track section underunsafe conditions in advance. For example, I will assume that relay H istie-energized as by the presence of a train in section B-C, so that atrain on track it entering section A-l3 will not close the circuit :tortransformer. S and the train will receive a more restrictive indication.If under these conditionsrelay R is de-energized, train govt-miningcurrent is supplied by transformer S to sect-ion E-F andthis current,flowing down the rails of section F l to point E, flows into secondary 5cl? transtormer T its a result train governing current is induced in.primary at of trans io-rn'ier T from which it may flow through linewires 12 and 12 to track transformer T The latter transformerWOdltllllQH in turn supply train governing current to the rails ofsection A-l3. it will. be observed, however, that this track transformerT is connected with the rails at the entrance end of the section A-B andtherefore the train occupying section ri li, under the conditionsoutlined above will not be aiiected by the train governing currentimproperly supplied to section A E as just explained. That to say, thistrain governing current is supplied to the section in rear of the trainand will therefore be shunted by the wheels and axles of the train sothat it has no effect on the-receiving apparatus. located in advance ofthe front axle of the train.

' fiimilarly, should relay R be de-energized improperly, and sectionA-l3 be occupied, track circuit current would llow from transformer Tthrough .the rails of section Dell, to transformer S thence throughwires 13 and 13, to transformer S and Elli] LI/l hence to winding 11 ofrelay R Vinding 10 of this relay is constantly supplied with trackcircuit current from line wires 12 and 12" and therefore relay R wouldbe energized under these conditions if the magnitude of the stray trackcircuit current in winding 11 were suiiiciently large. This straycurrent would however be extremely small due to the impedance of therails of section D-E,' and impedance 9 associated with transformers Sand S and so it would not ordinarily be of suiiicient magnitude toenergize relay R It will be observed however, that, should relay R beimproperly energized by such stray current, the circuit for transformerS would be opened (at contact 17 of relay R and the supply of straycurrent to winding 11 of relay R would be interrupted. it is, therefore,impossible with my invention for relay R to be held in the energizedcondition by such stray current.

The relative polarity of the track circuit current in each track sectionat a given instant is indicated by the plus and minus signs not enclosedin circles, and the relative polarity of the train governing current atthe same instant is indicated by such plus and minus signs enclosed incircles. It will be clear from the drawing that the train governingcurrents in all the track sections are of the same relative polarity,whereas the relative polarity of the track circuit current in eachsection is opposite to that of the track circuit current in the twoadjacent sections of the same track and the same that of the trackcircuit current in the corresponding section of the other track. Inexplaining the reason for this arrangement, I will assume that sectionsED and A-B are both unoccupied but that relays R and R are bothimproperly open. Under these conditions transformer T will cause trackcircuit current to be induced in line wires 13 and 13 throughtransformer S and transformer T will cause track circuit current to beinduced in line wires 13 and 13 through transformer S These two trackcircuit currents are of opposite instantaneous polarities, however, andtherefore will neutralize each other so that no track circuit currentwill actually be present in the train governing line wires 13' and 13Furthermore, train governing currents induced in the track circuit linewires 12 and 12 will counteract each other ina similar manner.

Referring now to Fig. 2, the reference characters 2 and "2 designate thetrack rails of a stretch of single track over which-traffic moves inboth directions. These rails are divided as before into a plurality ofsuccessive track sections AB,-B C, etc. Each track section is providedwith two track relays each designated by the reference character R witha suitable distinguishing exponent and one located at each end of thesection. Each. track relay comprises two windings 10 and 11, one ofwhich-windings, 10, is constantly supplied with alternating current froma suitable source such as an alternator J over line wires 12 and 12%Each track section is further provided with two track transformers, eachdesignated by the reference character T with an appropriate exponent.One such track transformer is located adjacent each end of each sectionand has a secondary winding 5 constantly connected through an impedance6 across the rails of the section for supplying. track circuit currentto the section. A traingoverning transformer having a secondary winding8 constantly connected through an impedance 9 with the rails of thesection is located adjacent each end ofe'ach section. Each such traingoverning transformer is designated by the reference character S with asuitable distinguishing exponent. Associated with each track relay R isa line relay designated by the reference character H with adistinguishing exponent. 'These line rela s are controlled in accordancewith the usua practice in absolute permissive block signaling systems,and since the control of these re lays forms no part of my presentinvention I have omittedthe circuits from the drawing for the sake ofsimplicity. For purposes of the present disclosure it is suflicient tostate that all line'relays are normally energized. lVhen a train movingfrom the leftto right leaves the first passing siding to the left of theportion of track shown in the drawing, line relays H, H, H etc. whichgovern traffic from right to left are de-energized and remain in thiscondition until the train has passed the first passing siding to theright of point C. Similarly, when train moving from right to left leavesthe. passing siding to the right of point C, re lays H H and H etc.which govern trafiic from left to right, become de-energized and remainin this condition until the train passes the lirst passing siding to theleft of. point A. Each H'relay' is further controlled so that when thecorresponding section becomes unoccupied the H'relay for the directionin which the train ismoving becomes energized.

Each section is also provided with a stick relay designated by thereference character-Q, with a suitable exponent and located adja centthe right hand end of the section. -A repeater relay designated bythereference character P with an exponent corresponding to the location isprovided forfeach track section and is located adjacent .the left handend of the section. Referring particularly to stick relay Q, this relayis provided with a pick-up circuit from which current flows from linewire 12% through wires 18 and 19,

back contact 200i relay R wire 21, back contact22 of relay R wire 23,front con tact 24; of relay H Wire 25, winding of relay Q and wires 26and 27 to line wire 12. 'llhiscircuit is closed only when relays and Eare ale-energized and relay H is energized, as when a train moving fromright to left enters section Al5, Relay H will then open its frontcontact and interrupt the circuit just traced, but relay Q will bemaintained in its energized conditions as long as any part of the trainoccupies section A-B by virtue of the sticl-z circuit which may betraced from line wire 12, through wires 28 and 29, back contact 30 ofrelay Wire'31, front contact of relay Q}, wire 83, winding of relay Qand wires 26 and 27 to line wire 12. When relay (If is energized,current flows from line wire 12, through wires 34 and 35, front contact36 of relay Q, Wire 87, winding of relay P, and Wires 38 and 39 to linewire 12. Relay P is therefore energized only when relay Qj is energized.Track circuit current is at times supplied to the primary t of traclrtransformer T, over a circuit which passes from line Wire 12, throughw'res and 40, back contact 41 of relay P wire e2, winding 4 oftransformer T, and wire 39 to line wire 12. This circuit is closedwhenever lay P is deenergizcd. The track transformer T located. at theright hand end of sectionA-B is supplied with track circuit current,when relay Q is ene 'ized, over a circuit which passes from line .wire12" 41 through wire 43, front contact 44L of relay Q wire 45, primarywinding 4; of transformer T, and wire 27 to line wire 19.

The second Winding 11 of relay R is connected through an impedance 15across the rails 2 and 2 of section i l-13 adjacent point A. When relayl? is energized, however, a path of low resistance is closed aroundinipedance 15, whichpath is through wire 41-6, front contact 47 of relayP and wire 48. When this path is closed, winding 11 of relay R isconnected directly across the rails of section AB. lVhen relay Q isde-energi'zed, winding 11 of relay 1& connected across the rails ofsection AB adjacent point B through hack contact 4:9, but when relay Q}is energized this winding 11 completely disconnected from the rails.

Train governing current is supplied to the track rails from analternator K over line wires 13 and 13 and through transformers Forexample, the circuit for transformer [t may be traced from line wire 13,through wire 50,'front contact 51 of relay H wire 52, back contact 53 ofrelay (sf, wire 54, primary .7 of transformer S wire 55, back contact 56of relay Ttfland wire to line wire 13. This circuit is closed only whenrelays Q and R are de-energized and relay H is energized. Then relay Pis energized and relay H is also energized, train governing current issupplied from line wire 13 through wire 58, front contact 59 of relayit, front contact 61 of relay P wire 62, primary 7 of transformer S, andwire 63 to line Wire 13.

As shown in the drawing all parts of the apparatus are in their normalpot tions, that is, the positons corresponding to the unoccupiedcondition of the stretch of traclt here shown. Under this condition thetrack transformer T located at the left hand end of each trac section issupplying traclr circuit current to the corresponding section, but t iscircuit for the track transformer located at the right hand end of'eachsection interrupted at a front contact of the corresponding stick relay.All traclrrelays are energized, all line relays H are energized, and allstick relays Q and repeater relays are Clo-energized. The impedanceassociated with the track relay at the left hand end of each section isconnected in series with the corresponding relay because the lowresistance path around this impedance is open, and winding ll of theother track for eachs ction is connected across the ra1ls by theassociated stick relay Q. All

train governing transformers S are de-ens crg'ized.

T will now assume that a train moving from left to right passes I throrh the stretch or rack shown 1n the drawing. As this tram. left thepassing siding to the left of point lst, line relays H", H and H became(ls-energized. he train enters section A.l3, relays R and PM become(ls-energized and relay H also becomes de-energ ized Relays and P areunaffected, but the closing of back contact 56 of trac; relay Rcompletes the circuit for transformer S which thereupon supgiilies.train governing current to section A- 3. the trainprointo sectionB-C,relay r and R become de-energized and relay H becomes de-encrgized.The closing of back contact 56 of relay B completes the circuit fortransformer s which then supplies 7. train governing current to sectionB'-C, and the de-energ ization of relay H interrupts the circuit fortransformers S" and so discon-- tinues the supply of train governing"current to sectionA-B. As the rear of the train passes out of sectionills--13 relays R" and R become energised hut the remaining apparatusi-sunaffected. the train passes out of section B C rela and if hccomecnergized, and as the t enters the passingsid inn" to the ll llt'tlfl'point C the energization of relnysll, H and li returns the tus to itsnormal position.v

I will now assume that train moving from right to left passes along thetrack. As such train leaves the first passing siding appara- Inn to theright of .JOlDlZ C, relays H, and

11 etc. become e-energized but theremaining apparatus remains unchanged.As the train enters section BC it causes the de-energization of relays Rand R Relay H also becomes de-energized, but subsequent to thede-energization of relay R and prior to the opening of front contact 524of relay H the pick up circuit for relay is closed. lhe re ay Q}subsequently gized condition over its sticl; circuit which includes itsown front contact 32 and back Contact 30 of'relay R lhe closing of frontContact 36 of relay Q closes the circuit for relay P which thereuponcloses its front contact. he opening o't back contact-4L9 of relay Q?disconnects winding 11 of relay R from the rails, and the closing offront contact 4.41 of relay Q" supplies alternating current to theprimary 4 of track transformer T Similarly, the opening of back contact4;]. of relay P opens thecircuit for transformer T and the closing offront contact ll of relay P completes the shunt around impedance l andconnects winding 11 of relay E directly to the rails of section B- Thede-energization of relay B does not complete the circuit for traingoverning transformer S because the circuit for this transformer is openat front cont-act 51 of relay H and also at bacl: contact of relay Q Theclosing of front contact 61 of relay P completes the circuit forprii'nary 'i' of transformer S because relay H is energized, i and underthese conditions section B'C is supplied with train governingcurrentfrom transformer S As the train moves through section AB theoperation of the apparatus is the same as just described for section BO.As the train moves out of section l3C track circuit current supplied tothe rails by transformer T energizes relay R which results in thede'energiaationof relay Q} and hence of relay 1. Relay R is there uponreconnected with the rails, the shunt around impedance for relay R isopened, and transformer T 1s energized. At th same time tracktransformer T is de-ener gized. The operation of the apparatus as thetrain passes out of section A-B will be readily understood withoutfurther expla nation. lVhen the train reaches the passing siding to theleft of point A, relays HQH"; and H again become energized to returi theapparatus to its normal condition.

It should be pointed out that with the ap paratus shown in Fig. 2 thetrack circuit cur rent is at all times supplied to an occupied tracksection by a track transformer located in the rear of the trainirrespective of the direction of travel of such train. It follows thatany stray train governing current prcsent in the transmission line forgenerator J or induced in any of the connections or circuits intendedfor track circuit current will not be efiective to produce an improperindication in the train governing mechanisnr for the reason that suchcurrent will be shunted away. from the receiving apparatus by the wheelsand axles of the train.

Although I have herein shown and de scribed only two forms of trackwayapparatus embodying my invention, it is understood that various changesand modifications may be mace therein within the scope of the, appendedclaims without departing from the spirit and scope of my invention.

'I'laving thus describedmy invention what I claim is:

1. In combination, a section of railway track along which trafiic movesin one direction, a source of alternating track circuit current of onefrequency connected with the rails adjacent the entrance end of saidsection, means controlled by traffic conditions in advance of saidsection for supplying alternating train governing current of a differentfrequency to the rails adjacent the exit end of the section, and a trackrelay receiving energy from the rails. adjacent the exit end of saidsection and responsive to said track circuit current but not to saidtrain governing current.

2. In combination, two sections of railway track, a track circuit foreach section comprising a track transformer connected with the railsadjacent the entrance end ofthe section and a track relay connected withthe rails adjacent the exit end of the section, a single transmissionline for supplying alternating track circuit current of one frequency toboth said transformers, and means for at times supplying alternatingtrain governing current of a different frequency to the rails of eachsection adjacent the exit end of the section.

in combination, two parallel sections of railway track over which'traiiic normally moves in opposite directions, a track circuit for eachsection comprising a track transformer connected with the rails adjacentthe entrance end of the section and atrack relay connected with therails adjacent the exit for supplying alternating track circuit currentof one frequency to both said transformers, and means for at timessupplying alternating train governing current of a differcnt frequencyto the rails of each section adacent the exit end of. the section.

of railway track, means for supplying each section with traincontrolling governing cur rent of one frequency adjacent the exit end fthe section, a track clrcult for each section including a track relaylocated at the exit en d of the section and a track transformer locatedat the entrance end of the section, and a single transmission line forsupplying track circuit current to said transformer, said transformersbeing so connected that the currents supplied to the two said secend ofthe section, a single transmission line 4. In combination, twosuccessive sections 7 tions thereby are of opposite relative polari tiesin the two sections at a given instant.

5. In combination, two sections of railway track, a track transformerfor each section connected with the rails adjacent the entrance end ofthe section trackway apparatus including a track relay foreaeh sectionconnected across the rails adjacent the exit end. of the section, asingle transmission line for supplying alternating current; of onefrequency to both said transformers, and. means for each sectioncontrolled by the associated track relay and by traffic conditions in.advance for supplying alternating train governing current of a differentfrequency to the rails of'each section adjacent the eXit end of suchsection.

6. In combination, two successive sections of railway track, two tracktransformers one connected with the rails adjacent the entrance end ofeach section, a single trans mission line for supplying alternatingcurrent'of one frequency to both said transformers,-two two-clementtrack relays each having one winding constantly supplied with energyfrom said tra emission line and the other windings connected across therails ad jacent the exit ends of said two sections re spectively, meansfor supplying alternating train governing current of a differentfrequency to the rails of each section adjacent the exit end of thesection, and means for each section for preventing the energization ofthe corresponding relay by said train governing current.

7. In combination, two parallel railway tracks each divided into aplurality of" successive sections and a train governing transformer foreach section connected across the rails adjacent the exit end of thesection, a first transmission line for supplying alternating traingoverning current of one frequency to all said train governing transformers, the circuits being such that the train governing currents inall said sections are of the same relative polarity at a given inst-ant,a track transformer for each section connected with the rails adjacentthe entrance end of the section, and a second transmission line forsupplying alternating track circuit cur rent of a different frequency toall said track transformers, the circuits being such that at a giveninstant the track circuit current in any section of either track is ofthe same relative polarity as the track circuit current in the adjacentsection of the other track and of the opposite relative polarity to thetrack circuit currents in the two adjacent sections of the same track.

current of one frequency connected with. the

rails adjacent the entrance end of said section, a relay responsive towere conditions in advance of said section, means controlled by saidrelay for supplying alternating train governing current of a differentfrequency to the rails adjacent the exit end of said section, and atrack relay receiving energy from the rails adjacent the exit end ofsaid section and responsive to said track circuit current but not tosaid train governing current.

9. In combination, a railway track divided into sections, a source ofalternating track circuit current of one frequency connected with therails adjacent the entrance end of each section, a. track relay for eachsection. connected with the rails adjacent the exit end of each section,and means controlled by each track relay for supplying alternating traingoverning current of a different frequency to the rails adjacent theexit end of the section next in the rear.'

10. In combination, a railway track divided into sections, asource ofalternating track circuit current of one frequency connected with therails adjacent the entrance end of each section, a track relay for eachsection connected with the rails adjacent the exit end of eachsection,and means controlled by each track relay for supplying alternating traingoverning current of a difl'erent frequency to the rails adjacent theexit end of the section next in the rear each track relay beingresponsive to track circuit currentbut not to train governing current.

11. In combination, a railway track divided into sections, a source ofalternating track circuit current of one frequency connected with therails adjacent the entrance end of each section, a track relay for eachsection connected with the rails adjacent the exit end of each section.and means controlled by each track relay for supplying alternating traingoverning current of different frequency to the rails adjacent the exitend of the sectionv next in the rear'cach track relay being responsiveto track circuit current but not to train governing current, and thetrain governing current being of the same frequency in each section.

In testimony whereof I affix my signature.

ROBERT M. ernson.

